View source for BL 13.5 inch naval gun Mk I – IV

{{Infobox Weapon
|name= Ordnance BL 13.5 inch gun Mk I - IV
|image=[[Image:HMS Hood 13.5 inch forward gun turret.jpg|300px]]
|caption=Forward turret of [[HMS Hood (1891)|HMS ''Hood'']]
|origin= [[United Kingdom]]
|type= [[Naval gun]]
<!-- Type selection -->
|is_ranged=YES
|is_bladed=
|is_explosive=
|is_artillery=YES
|is_vehicle=
|is_UK=YES
<!-- Service history -->
|service=
|used_by={{UK}}<br>{{ITA}}
|wars=
<!-- Production history -->
|designer= [[Armstrong Whitworth#Elswick Ordnance Company|Elswick Ordnance Company]]
|design_date=1880
|manufacturer=
|production_date=
|number=
|variants=Mk I, II, III, IV
<!-- General specifications -->
|weight=67-69 tons barrel & breech<ref name=Gunnery1902/> 
|length= 
|part_length={{convert|405|in|m|sigfig=4}} bore (30 [[Caliber#Caliber as measurement of length|calibres]])<br><ref name=Gunnery1902>Text Book of Gunnery 1902, Table XII, Page 336</ref>
|width=
|height=
|crew=
<!-- Ranged weapon specifications --> 
|cartridge= {{convert|1250|lb|kg}}<ref name=Gunnery1902/>
|caliber={{convert|13.5|in|mm|sing=on|sigfig=4}}
|action= 
|rate=
|velocity= {{convert|2016|ft/s|m/s|sigfig=3}}<ref>1,250 lb shell, with 630 lb [[List of British ordnance terms#S.B.C.|Slow-burning Brown Prismatic powder]] or 187 lb cordite size 44. Text Book of Gunnery, 1902.</ref>
|range= {{convert|12000|yd|m}}<ref name=Gunnery1902/>
|feed= 
|sights= 
<!-- Artillery specifications -->
|breech=
|recoil=
|carriage=
|elevation=
|traverse=
}}
The '''[[British ordnance terms#BL|BL]] 13.5 inch naval gun Mk I''' ("'''67-ton gun'''") was Britain's first successful large [[Rifled breech loader|breechloading]] [[naval gun]]. Mks I - IV were all of 30 [[Caliber#Caliber as measurement of length|calibres]] length and of similar construction and performance.

==United Kingdom Service==
===Royal Navy service===
[[Image:HMS Empress of India Stern Drydock Clip Guns.jpg|thumb|left|300px|<center>[[HMS Empress of India (1891)|HMS Empress of India]] in drydock, showing stern barbette mounting</center>]]
The gun was designed to match the new large guns of the French ''[[Amiral Baudin class battleship|Amiral Baudin]]'' class battleships. Development and manufacture occurred very slowly. It was originally intended to equip the [[Admiral class battleship]]s,{{Fact|date=July 2009}} begun in 1880, but delays led to [[HMS Collingwood (1882)|''Collingwood'']] being equipped with inferior [[BL 12 inch naval gun Mk I - V|12 inch guns]] and [[HMS Benbow (1885)|''Benbow'']] with the subsequently unsuccessful [[BL 16.25 inch Mk I naval gun|16.25 inch guns]].

The remaining Admiral class ships [[HMS Anson (1886)|''Anson'']], [[HMS Camperdown (1885)|''Camperdown'']], [[HMS Howe (1885)|''Howe'']] and [[HMS Rodney (1884)|''Rodney'']] were eventually completed in 1889 equipped with 4 13.5 inch guns each, in twin barbettes on the centreline at each end of the superstructure.

The guns also equipped the subsequent [[Trafalgar class battleship|''Trafalgar'']] class laid down in 1886 and [[Royal Sovereign class battleship|''Royal Sovereign'']] class battleships laid down in 1889.

===Coast defence service===
A single Mk III gun was mounted as a [[disappearing gun]] for coast defence at [[Penlee Battery]], Plymouth.<ref>[http://www.palmerstonforts.org.uk/art/gun2.htm#bl Palmerston Forts Society]</ref>

==Italian Service==
[[File:Re Umberto 13.5 inch gun barbette right elevation.jpg|thumb|left|300px|<center>Barbette mounting on ''Re Umberto''</center>]]
Guns were also sold to Italy to arm the [[Re Umberto class battleship|Re Umberto class battleships]] '''Re Umberto''', '''Sicilia''' and '''Sardegna''', laid down in 1884 and finally commissioned in 1893 - 1895.
<br style="clear:left;" ><!--don't delete this, it forces next heading to nicely follow below the Images-->

==See also==
{{commonscat-inline|BL 13.5 inch naval gun Mk I - IV}}
*[[340mm/28 Modèle 1881 gun]] French equivalent
*[[List of naval guns]]

==Notes==
{{reflist}}

==References==
*[http://cgsc.cdmhost.com/u?/p4013coll11,230 Text Book of Gunnery, 1902. LONDON : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE, BY HARRISON AND SONS, ST. MARTIN'S LANE]

==External links==
*Tony DiGiulian, [http://www.navweaps.com/Weapons/WNBR_135-30_mk1.htm British 13.5"/30 (34.3 cm) Marks I, II, III and IV]
*[http://www.palmerstonforts.org.uk/art/13-5blh.htm Diagram showing gun on disappearing mounting, as mounted at Penlee Battery, Plymouth] at Palmerston Forts Society website


{{VictorianEraBritishNavalWeapons}}

[[Category:Naval guns of the United Kingdom]]
[[Category:Naval guns of Italy]]
[[Category:343 mm artillery]]
[[Category:Elswick Ordnance Company]]

[[Category:2Fix]]